A prospective and controlled clinical study to evaluate the effect of ascending aortic reconstructive surgery on cardiovascular hemodynamics

From niml.org

If you would like to help with this study as a master's or bachelor's thesis project, please send Bryn Martin an email with your resume and research interests.


The problem

Figure 1. Experiment conducted by N. Stergiopulos et al. to investigate the influence of wrapping the aorta with Dacron fabric in a porcine model (Ioannou, Stergiopulos et al. 2003).
Figure 2. Hemodynamics induced after aortic elasticity reduction by wrapping the proximal aorta with Dacron fabric. Note, after banding the aortic pressure increases and blood flow decreases.

Proximal aortic compliance provides more than one-half of the entire systemic arterial compliance. Thus, when an aortic graft patient has part of their aorta replaced with an inelastic graft, it is expected that the graft will have a significant impact on aortic pulse and peak pressure and cardiac afterload, all factors related with hypertension. A previous study conducted by our research group on a porcine model (Figure 1) revealed that wrapping the aorta with Dacron fabric resulted in a large increase in systolic pressure and reduction in aortic blood flow (Figure 2) (Ioannou, Stergiopulos et al. 2003). However, a detailed study comparing pre and post surgical hemodynamics in ascending aortic graft recipients has not been conducted.

Hypothesis and research objectives

We propose to examine the pre and post surgical impact of aortic reconstructive surgery on cardiovascular hemodynamics and hypothesize that aortic and total arterial compliance will be reduced significantly.

Methods and study outline

To be posted.

Expected results and potential impact

The proposed work will quantitatively assess the hemodynamic impact of implantation of a synthetic aortic graft. It is expected that aortic compliance will be reduced after graft implantation. Thus, the methodology developed in this pilot study could be further explored to compare hemodynamic impact of different type of aortic grafts on the market and help assess new aortic graft designs.

Preliminary results

To be posted


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Ioannou, C. V., N. Stergiopulos, et al. (2003). "Hemodynamics induced after acute reduction of proximal thoracic aorta compliance." Eur J Vasc Endovasc Surg 26(2): 195-204.

Stergiopulos, N., P. Segers, et al. (1999). "Use of pulse pressure method for estimating total arterial compliance in vivo." Am J Physiol 276(2 Pt 2): H424-428.

Stergiopulos, N., D. F. Young, et al. (1992). "Computer simulation of arterial flow with applications to arterial and aortic stenoses." J Biomech 25(12): 1477-1488.

Westerhof, N., P. Sipkema, et al. (1972). "Forward and backward waves in the arterial system." Cardiovasc Res 6(6): 648-656.